I've lived in the Quad Cities forever, and I had never heard of the place either. The one we went to is in Bettendorf's Crow Creek Park, near 53rd Avenue and Devil's Glen road. Google maps (satellite view) shows a hint of decent visibility along the shore, and a touch of green water compared to the brown soup we normally get around here.

The quarry dive did feel a little cave inspired, if that makes sense. We did lots of cruising near the edges, and it was neat to see the rock walls and all the boulders down there. Once in a while someone would hit the bottom or brush up against a muddy rock, and poof, you couldn't see anything but brown. I kept an arm on my dive buddy, or my hand on the rope down at the training platform, and thought it was rather interesting experience.

Will sign up on that board, thanks!

Letting the days go by / water flowing undergroundInto the blue again / in the silent waterUnder the rocks and stones / there is water underground.